1. Field of the Invention
The present invention relates to an adjustable deadlatch. Specifically the invention relates to a deadlatch which is adjustable between a 23/8" or a 23/4" backset.
2. Description of the Prior Art
Entry doors are typically made to accept deadlatch locks having backsets of either one of two sizes. The normal wooden household door typically uses a deadlatch lock having a backset of 23/8". Heavy duty metal doors which may be used for commercial or industrial purposes or may be used for residential purposes, typically has a deadlatch lock having a backset of 23/4". These metal doors are normally sold with a premade opening for a 23/4" backset for the latch.
In the past, separate deadlatches were used depending upon the particular backset. Specifically, if the door required a deadlatch having a 23/8" backset, a deadlatch having this dimension was used with the lock. On the other hand, if the door required a deadlatch with a 23/4" backset, this size deadlatch was provided even though the remaining portions of the lockset might be identical to the lockset used with the 23/8" backset latch. In other words, the only difference between the locks for use with either the 23/8" or 23/4" backsets was the deadlatch itself.
It has, therefore been considered desirable to provide for an adjustable deadlatch that can be used for either a 23/8" or 23/4" backset. This would eliminate the cost of manufacturing two separate deadlatches and would also eliminate the necessity of stocking a double inventory for complete lock sets or for deadlatches. An adjustable deadlatch could, therefore, greatly simplify the inventory requirement and thereby reduce the cost of stocking this double inventory.
Unfortunately the adjustable deadlatches provided by the prior art have been complicated in structure and cumbersome in operation. For example, one such structure includes a number of arm members which must be pivoted out of the way such as by a pin member extending outwardly from the deadlatch. The pin member is then pushed to translate a portion of the latch structure between the 23/8" and 23/4" backset positions. The arm members must then be pivoted back to lock the structure deadlatch in position. Other prior art devices include removable pieces which must be extracted and repositioned or removed completely and all of these prior art devices do not provide for a simple, reliable and easily operated adjustable deadlatch latch.